Device for the automatic feeding of tandem mills



6 Sheets-Sheet l INVENTOR.

ATTORNEYS E. B. HUDSON July 2, 1935.

DEVICE FOR THE AUTOMATIC FEEDING OF TANDEM MILLS Filed March 9, 1932 Maw www E. B. HUDSON 2,006,764

DEVICE FOR THE AUTOMATIC FEEDING 0F TANDEM MILLS July 2, 1935.

Filed March 9, 1932 6 Sheets-Sheet 2 I N VE TOR.

A TTORNEYS 6 Sheets-Sheet 3 E. B. HUDSON Filed March 9, 1952 INVENTOR.

W V W ATTORNEYS DEVICE FOR THE AUTOMATIC FEEDING OF TANDEM MILLS July 2, 1935.

P\cel'my Pas/ Ion E. B. HUDSON July 2, 1935.

DEVICE FOR THE AUTOMATIC FEEDING OF TANDEM MILLS Filed March 9, 1932 6 Sheets-Sheet 4 v INVENTOR. flaw Q m A TTORNEYS E. B. HUDSON July '2, 1935.

DEVICE FOR THE AUTOMATIC FEEDING 0F TANDEM MILLS Filed March 9, 1952' 6 Sheets-Sheet 5 INVENTOR.

fi vhs [WI/n Has/170113 PKWQIRJSIIIOR y E. B. HUDSON 2,006,764

DEvI cElFoR THE AUTOMATIC FEEDING 0F TANDEM MILLS v v Filed March 9, 1952 s Sheets-Sheet 6 Power V su ly INVENTOR.

A TTORNEYS Patented July 2, 1935 UNITED STATES PATENT OFFICE DEVICE FOR THE AUTOMATIC FEEDING or TANDEM MILLS Edwin B. Hudson, Middletown,

The American Rolling Mill Company,

Ohio, assignor to Middle- 7 Claims.

The earlier type of cold mills used for the reduction of gauge of cold strip was a two-high type, and the maximum width rolled generally did not exceed twelve inches. The feeding of cold strip into mills of this size and type presented no serious problems and could be done manually without great physical effort on the part of the operators as the cold strip, due to its narrow width, could be easily handled.

The development of the four-high cold mill greatly increased the width of cold strip which could be rolled, due to the more rigid structure of this type of mill and the reduction of spring in the rolls which made it possible to roll with controlled gauge across the strip. But with the introduction of the wider type of cold mill, particularly the four-high type, and the growth of a continuous rolling, there was no improvement in method of feeding these mills. The manual method employed to feed the narrow mills was still used on the mills of the wider type, that is, strip thirty-six inches and wider. To maintain economical mill speeds and to insure a uniform product on the wider mills when manually fed is impracticable, due to the fact that strip of such width as thirty-six inches, more or less, is beyond the physical capacity of the operators to handle, and this work is now only accomplished at great hazard to both the operators and equipment.

The arrangement of cold mills in both the twohigh and four-high type is generally two to five mills in tandem, each mill making a successive reduction in gauge so that in one pass through the tandem mills the strip is reduced to the desired thinness. The tandem mills are so spaced that the cold strip is at times in all mills at the same time.

To guide the strip from one mill to the next succeeding mill, and properly to enter the strip in the succeeding mill is not simple. There are several complications. First, to guide the strip laterally in a horizontal plane is diflicult as it is impossible to turn the piece in the preceding mill. Second, the strip upon entering the suc-.

ceeding mill must be held in its proper position by unyielding side guides to prevent the strip from running off the roll into the roll necks and seriously damaging the mill. 0n the present types of mill, both wide and narrow, side guides are provided, usually of brass, which are set to the proper width by shimming up behind them. Hence, there is practically no yielding to strip pressure. It must be understood that although these side guides are capable of adjustment to take the diilerent widths of strip, no provision is made to open the guides to facilitate the entry of the strip between the guides; and the maximum fixed clearance between the guides exceeds the strip width only by one-eighth to three-sixteenths of an inch. The small clearance between guides not only makes entry of the strip dimcult, but at the same time presents too wide a clearance to guide the strip perfectly.

It is a primary object of my invention to pro- 10 vide a guiding mechanism which facilitates the entry of the strip into the rolls. It is another fundamental object of my invention to provide a mechanism which will feed strip automatically into tandem mills, particularly cold mills, in proper feeding and guiding relationship.

These and more specific objects of my invention which will be apparent to one skilled in the art upon reading these specifications, I accomplish by that certain construction and arrange- 2o ment of parts of which I shall now describe a preferred embodiment. Reference is had to the drawings, wherein:

Figure 1 shows the schematic arrangement of this invention in plan.

Figure 2 shows the schematic arrangement in elevation.

Figure 3 shows details of the aligning machine for guiding the free end of the strip from the mill table to the guiding machine which is fastened to the mill, housings.

Figure 3a is an end view of the aligning machine of Figure 3.

Figure 4 shows a detail section along the center line of the mill of the guiding machine mounted directly between the mill housings on the entering side.

Figure 5 shows a half section and a half elevation of the guiding machine looking in the direction of rolling.

Figure 6 shows half plan of the guiding machine in the rolling position and half plan in the receiving position.

Figure '7 shows schematic arrangement of the air and electrical connections for controlling the movements of the machine.

Figure 8 shows electro-pneumatic control valve.

This invention includes a guiding machine provided with unyielding side guides, which, however, automatically open to receive the strip and automatically close after the strip has been entered the proper distance. The strip is held securely on the edges and on the upper and lower surfaces, the relation of the strip to the guiding machine being such that the leading end of the strip pro- Jects beyond the end of the side guides such a distance as is necessary to permit the strip to be in-- serted between the mill rolls upon the forward movement of the guiding machine. The machine is automatic to the extent that when the strip is entered either manually or by other means until the strip projects the proper distance beyond the sideguides, the machine then will automatically close the side guides against the edges of the strip, hold the strip securely on the upper and lower surfaces, and will insert the strip between the mill rolls. The machine will remain in operative position until the entire length of strip passes through the mill. Afterward it will return to the receiving position for the next strip.

It must be understood that although the guiding machine is automatic within itself, the strip has to be entered, either manually or by other means. It would then follow that a single mill or a set of tandem mills could be operated with much less efiort on the part of the operator, and at higher surface speeds with the guiding machine alone than has hitherto been possible with ordinary equipment.

To make the feeding of cold strip fully automatic on a tandem mill, it is necessary to provide a device which leads the strip from the preceding mill and properly enters it into the guiding machine. This aligning machine, which consists of a pair of cantilever pinch rolls (Figs..1, 2, and 3), is located in the mill tables just ahead of the guiding machine; and its function is to receive the strip in its more or less misaligned position, align the center line of the strip to coincide with the center line of the mill, and enter the strip along the center line of the mill into the guiding machine. The guiding machine will then automatically functiomproperly entering the strip into the mill and guiding the strip during the entire rolling operation.

It would follow that for semi-automatic operation, the guiding machine for each mill is necessary, and for full automatic operation that the guiding machine in combination with the aligning machine is necessary on all mills except the first To guide the cold strip properly through the cold mill during the rolling operation, it is necessary that the edges of the strip be held in proper alignment by unyielding side guides, and that the upper and lower surface of the strip be retardedso that the strip will enter the cold rolls flat and without buckling. To facilitate the entry of the strip between the side guides by mechanical means, it is necessary that the side guides be opened slightly. Due to the limited space between the mill housings the maximum opening of the guides will not exceed two inches more or less. For this reason, and also because the strip as it is delivered from the preceding mill may tend to run off the center line of the succeeding mill,

means are preferably provided to enter the leading end of the strip properly into the guiding machine which is positioned between the mill housings on the entering side of the mill.

In the schematic arrangement shown on Figures 1 and 2, the mill housings I support the working or mill rolls 2. The table carrying the strip from the preceding mill is indicated as 3 with an adjustable side guide 4 on the operating side of the mill. This guide is set about one inch clear of the strip when the strip is in proper alignment. The side guide 5 is set with its short portion near the mill so adjusted as to be in line for entering the strip into the mill, while the fore part of this guide is about one inch farther from the center line of the mills as shown. I provide aligning means comprising cantilever type pinch rolls 8 and 6 (details shown in Fig. 3) rotatively mounted upon horizontally disposed members, and also mounted for horizontal revolution about a pivot point I. These rolls are held normally in the angular position 8 (Fig. l) but are free to rotate about pivot point 1 against the tension of strip advances from the preceding mill by which it is propelled in the position indicated at a (in which it may then be out of contact with guide 5), to point "12, where it comes into contact with pinch rolls 6. These move the strip in the direction indicatedby arrow i4 until the edge of strip contacts with guide 5. Pinch roll 6 can then no longer drive the strip as indicated by arrow l4 due to the resistance of guide 5; but due to the traction of pinch roll 6 on the strip, which traction is resisted by spring 9. the pinch roll 6 turns about pivot point I to position 6 propelling the strip between open side guides I! as indicated by the arrow l5, through position "0 and then to position d. The pinch roll remains in position 6' until the tail end of the strip has passed it; then it returns to position 6 by the action spring 9, in readiness for the next step. The strip runs from position d to position e" under the rotating flag l3, which permits the passage of a suflicient amount of the strip to reach position e, before it closes the necessary elec-' end of guide I! to the extent indicated by position e which is the same as the relation of the end of guide I! and position I. In closing down on the edges of the strip, the guides I! move therewith. Thus, when contact of guide I2 is made with the sheet as indicated by arrow l6, guide I! then moves in the direction indicated by arrow I 1 putting the projected end of the strip between the mill rolls. The guides remain in this position until the tail end of the strip passes rotating flag l3, which then returns the guides I! to position I2 to receive the next strip.

This explanation, taken in connection with Figures 1 and 2, which are diagrammatic, will illustrate the principle of action of my device.

Figure 3 shows the general design of the aligning machine comprising the cantilever type pinch rolls 6 which are mounted by means of shafts 25- and 26 on the pedestal base It. The upper structure l 9 is rotatably mounted on the base to swing about pivot line I against the tension of spring 9. Its motion is limited by set screw i I.

The lower of the pinch rolls 6 is driven by an adjustable speed motor through pulleys 2|, 22,-

shaft 25 supporting lower pinch roll 6 is mounted in suitable hearings in housing l9, whereas shaft 26 supporting upper pinch roll is mounted in a special casting 21, which is in turn mounted in housing l9, and can rock vertically, to a slight extent, a pivot 28. It has no movement in a lateral plane.

The pressure between pinch rolls 6 is regulated by screw 29 and spring 30.

In my guiding machine the members having the guiding surfaces are controlled by cooperating wedge-shaped surfaces so that any movement thereof in feeding direction will serve to bring the guides from either side inwardly toward and against the edges of the strip.

Figure 4 shows a detailed arrangement of the guiding machine taken as a section along the center line of the mill in the direction of rolling. Referring to Figures 4, 5, and 6, the standard mill housing supports the working rolls 2, 2, and back-up rolls 2 and 2'. The guiding machine consists of a supporting structure 3| fastened rigidly to the mill housings This supporting structure is held across the lower portion by casting 32, and across the top by casting 33, mounted on the mill housings.

A ram 34 is slidably mounted in casting 32, and is held in its proper position by plates 35. The ram 34 carries two cross dowels 36 mounted at right angles to the direction of ram travel. These engage side plates 31 as shown. Springs 38 are provided to keep wedge plates 38 and 40 in contact. These control the lateral movements of side plates 31. Wedge 39 is rigidly mounted to side plate 31, whereas wedge 40 is mounted in the supporting structure 3|. The wedge surfaces of the wedges 39 and 40 are so proportioned that the first third of the travel of ram 34 from receiving position to rolling position completes the lateral movement, bringing side guides l2 into contact with the edge of the strip before the strip is entered between the mill rolls 2. The ram 34 may be actuated by an air cylinder 4|, having the piston 42, piston rod 43, linkage 44 and 45. The air cylinder is provided with ports 46 and 41, and also may have built in dash pots 48 and 49 to control the piston action. Mounted in side plates 31 are the bronze side guides |2 which are adjustable to width of strip by lateral movement in relation with the center line of the strip, for widths under that of the maximum capacity. The guides l2 may be backed up between the back of these members and the side plates 31 by wood strips (not shown). Side guides |2 are held in position by a set screw 59, engaging the casting which is held in position by bolts 52 to side plates 31.

Slidably mounted directly under side plates 31 are the hold down boards 53, preferably extending the width of the strip less 2". The boards 53 are supported by the projecting ends of side plates 31 at g, acting as guides operating upon such a slope that movement away from the mill causes boards 53 to raise up from the strip and movement in the opposite direction causes them to move down into contact with the strip. Cover plate 54 is spiked to boards 53 acting as a support in side plate guides 31. The plate 54 is provided with connection 55 to engage piston 56.

The movements of boards 53 are controlled by an air cylinder 60 and piston rod 56 engaging connection 55 as shown. Air cylinder 68 is provided with ports 51 and 56. The rear end of the cylinder 69 is supported by links 59 engaging the side plates 31. This allows a lateral movement of side plates 31.

The top board 53 is cut away to provide clearance for the flag |3 as shown. The ram 34 and side plates 31 are covered by lower boards 6| as shown. Clearance is also provided in lower boards 6| for flag l3. Top boards 53 and lower boards 6| preferably have a width 2" less than that of the strip to be rolled. The side plates 31 are held in position by an angle plate 62 and the hold down guide 63, which are fastened to the top support 33, as shown.

The automatic operation of the machine is controlled by flag l3, which, in its preferred form, is a wheel mounted on shaft 64 in casting 65, which, in turn, is supported by a hinge 66 on the side plate 31. A spring 61 brings the flag down against the strip, with the movement limited by a nut 68. The flag wheel I3 is so adjusted that it rotates less than one revolution (thus paying out the strip beyond ram 34 a suflicient distance to permit it to enter the rolls 2 on the forward stroke), before it closes the electric circuit which it controls. The limited rotation of the flag I 3 is determined by the stop pin 69 which engages the casting 65. The flag I3 is rotated by the strip in a counterclockwise direction (Fig. 4); but a spring 10, engaging the shaft 64, returns it to the starting position after the strip leaves the machine. On the shaft 64, and rotated by flag I3, is mounted a commutator 1| having commutator bars 12 and brushes 13 and 14. This device closes the electrical circuit to operate the electro-pneumatic valve (Fig. 8).

Figure '7 shows the air and electrical connections in the form of a diagram, showing the shaft 64 of flag |3 with the commutator 1|, commutator bar 13, brushes 13 and 14, an electropneumatic valve 15, electric solenoid 16, and balanced valve 11, held normally in the receiving position by spring 18, and having a connection to the air supply at 19, a port for rolling position at 80, and a port for receiving position at 8|. These ports connect respectively with air cylinder 4| at ports 46 and 41 also with air cylinder 60 at ports 51 and 58.

The operation of the machine may be briefly described as follows: The machine is normally in the receiving position, i. e., with the side guides l2 open and the top board 53 up, with no current flowing through the solenoid and with port 8| in valve 15 uncovered by spring 18. With the machine in this position the strip enters, aligned either manually or otherwise, until the strip rotates flag l3 the proper distance, thereby closing the circuit through brushes 13 and 14, and energizing solenoid 16. Thereby port 89 is connected to the air supply, causing pistons 43 and 56 to move to rolling position. The first third of the stroke on piston 43 brings the side guides |2 into contact with the strip. The top board 53 also makes contact in the early part of the stroke. The strip is thus held firmly, with the leading end projecting beyond the end of ram 34 the proper distance. On the last twothirds of the stroke the strip is entered between the mill rolls 2. The machine remains in the rolling position until the rear end of the strip passes flag I3, which then returns to receiving position by spring 10. This immediately breaks the electrical contact, de-energizing the solenoid 16, whereupon spring 18 returns the valve to receiving position, uncovering port 8|. The operation as described represents the complete cycle for each strip, and is repeated of course, for succeeding strips.

It will be clear'that modifications may be made in my described structure by those skilled in the 5 art without departing from the spirit of my inwidth of the piece to be rolled, and movable in the direction of piece travel, means for frictionally grasping said piece on its upper and lower surface, means for contracting,said side guides to grip against the piece edges during said movement, said contracting means and grasping means arranged to act on the sheet at the same time, and after the sheet has entered in between the side strips, and means for effecting said coaction, said means comprising sheet-actuated control means arranged to permit a predetermined free travel of said sheet.

2. In combination with a rolling mill, 9. guiding and aligning device comprising side guides normally spaced a greater distance apart than the width of the sheet to be rolled, means for frictionally grasping said sheet on its upper and lower surface, means for contacting said side guides against the sheet edges, said contracting means and grasping means arranged'to act on the sheet at the same time, and after the sheet has entered in between the side strips, and means for effecting said coaction, said means comprising sheet-actuated control means arranged to permit a predetermined free travel of said sheet, and automatic meansfor aligning said sheet to feed it between said guiding means.

3. In combination with a rolling mill, a guid- I ing and aligning device comprising side guides normally spaced a greater distance apart than the width of the sheet to be rolled, means for frictionally grasping said sheet on its upper and lower surface, means for contracting said side guides against the sheet edges, said contracting means and grasping means arranged to act on the sheet at the same time, and after the sheet has entered in between the side strips, and means for effecting said coaction, said means comprising sheet-actuated control means arranged to permit a predetermined free travel of said sheet, and means for maintaining the engagement of .said guiding and gripping means throughout the travel of said sheet.

and aligning device comprising side guides normally spaced a greater distance apart than the width of the sheet to be rolled, means for frictionally grasping said sheet on its .upper and lower surface, means for contractingsaid side guides against the sheet edges, said contracting means and grasping means arranged to act on the sheet at the same time, and after the sheet has entered in between the side strips, and means for effecting said coaction, said means comprising sheet- -actuated control means arranged to permit a predetermined free travel of said sheet, and means for maintaining the engagement of said guiding and gripping means throughout the travel of said sheet, said means comprising a sheet-actuated flag, an electrical circuit controlled thereby, and power means actuating said guiding and gripping means;

5. In combination with a rolling mill having guiding means, means for feeding sheet to be rolled into said guiding device, said means comprising feeding rolls having axes normally at an acute angle to the center line of said mill, and a stationary side guide member against which said sheet is forced, said rolls mounted to swing against the travel of said sheet to a position in which their axes are normal to the center line of said mill.

6. In combination with a rolling mill having guiding means, means for feeding sheets to be rolled into said guiding device, said means comprising feeding rolls havingaxes normally at an acute angle to the center line of said mill, and a stationary side guide member against which said sheet is forced, said rolls mounted to swing against the travel of said sheet to a position in which their axes are normal to the center line of said mill, and means for limiting said swing.

7. In combination with a rolling mill having guiding means, means for feeding sheets to'be rolled into said guiding device, said means comprising feeding rolls having axes normally at an acute angle to the center line of said mill, and a stationary side guide member against which said sheet is forced, said guiding means comprising side guide members movable with said sheet, means for moving said members, and means for bringing said members against the side edges of said sheet during said motion.

EDWIN B. HUDSON.

4. In combination witha rolling mill, a guiding 

